Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Ergebnis 4 von 381
Marine geophysical researches, 2022-09, Vol.43 (3), Article 33
2022
Volltextzugriff (PDF)

Details

Autor(en) / Beteiligte
Titel
Glacial sediments on the outer Chukchi Shelf and Chukchi Borderland in seismic reflection data
Ist Teil von
  • Marine geophysical researches, 2022-09, Vol.43 (3), Article 33
Ort / Verlag
Dordrecht: Springer Netherlands
Erscheinungsjahr
2022
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
  • The up to 900 km broad shelves off East Siberia and northwest off Alaska, including the Chukchi Shelf and Borderland, are characterized by shallow water in the periphery of the Arctic Ocean, north of the Bering Strait. Seafloor investigations revealed the widespread presence of glacial bedforms, implying the former existence of grounded ice in this region. We discuss the erosion and deposition around and beneath ice sheets/shelves using a regional grid of 2D seismic reflection data, acquired in 2011 from R/V Marcus G. Langseth across the outer ~ 75 km of the Chukchi Shelf and the adjacent Chukchi Borderland. A high amplitude glacial base (GB) reflection extends over large parts of the shelf, separating glacial from preglacial strata. We define eleven seismic reflection characters, that we use to infer distinct depositional environments of glacial sediments. Thick well stratified sediments overlying the GB reflection in the south may have been impacted by fewer advance-retreat cycles than those near the northeastern and western shelf breaks. Here, the GB reflection pinches out at the seafloor next to reworked and eroded areas. Numerous meltwater channels, some up to several kilometers wide, together with grounding zone wedges and recessional moraines are hints for ice sheets in the Chukchi Region. These ice sheets built up a huge grounding zone wedge of 48 km × 75 km on the Chukchi Rise. More grounding zone wedges on the western sides of bathymetric highs of the Chukchi Borderland along with mega scale glacial lineations indicate later ice shelf advances from east during the late Quaternary. However, in the absence of deep sediment cores, the timing or origin of the ice grounding events cannot be fully reconstructed.

Weiterführende Literatur

Empfehlungen zum selben Thema automatisch vorgeschlagen von bX